Internal alignment clamp for girth welding



www

. Sept 3, 1957 I.1. B; TIEDEMANN 2,804,836

INTERNAL ALIGNMENT CLAMP FOR GIRTH WELDING Filed July ll, l952 5SheAetS-Sheet 1 JuZiusB. Tiedemann yhwvw ATTQRNEYJ.

Sept 3, 1957 J. B. TlEnl-:MANN 2,804,836

INTERNAL ALIGNMENT CLAMP FOR GIRTH WELDING Filed July ll. 1952 3Sheets-Sheet 2 INVENTOR. Julz'LzsB. Tiedemann BY @uw el wm mm QM A ,L

Sept. 3, 1957 J. B. TIEDEMANN 2,804,836

INTERNAL ALIGNMENT CLAMP FORGIRTH wELDrNG Filed July l1, 1952 3 Sheetssheet 3 Q' N Q. 5 9. E

LL, LL.

Q Q Q I ,w

Q Q \D Q Q E I Q Q *n Q :n m LO kO n W kn A *n LO n o l@ h l m KO L15 (Dkh "l N .s N LQ l l 1"/ Ch f/ D l@ I w W m l' w K Gw KQ l l0 1NI/ ENToR-Julzus B. Tze demazm ATTORNEYS.

INTERNAL ALIGNMENT CLAMP FOR GIRTH WELDING Julius B. Tiedemann,Milwaukee, Wis., assignor to A. 0. Smith Corporation, Milwaukee, Wis., acorporation of New York Application July 11, 1952, Serial No. 298,392

9 Claims. (Cl. 113-103) This invention relates to a welding alignmentclamp and more particularly to a clamp to be employed to internallyalign the adjacent ends of two pipe sections to be welded together.

An object of the present invention is to provide a clamp for aligningthe adjacent ends of two pipe sections in proper welding position andfor supporting the molten weld metal during welding of said ends.

Another object of the invention is to provide an intcrnal weldingalignment clamp which will effectively align and restore the circularconfiguration of pipe sections of distorted cross section.

Still another object of the invention is to provide an expandableinternal alignment clamp whereby the clamp is expanded in purely radialdirection in order to achieve a maximum expanding force.

A further object is to provide an internal welding clamp havingauxiliary positioning means whereby the clamp may be maintained inproper alignment within a pipe section before the main clampingapparatus is expanded into contact with said pipe sections.

In the past ditiiculty has frequently been encountered when attemptingto align the adjacent ends of pipe sections in proper Welding positionwhen one or both of the pipe sections are oval or otherwise distorted incross section rather than being perfectly circular. The conventionalinternal alignment clamp utilizing radially expanding shoes or clampingmembers has considerable diiculty in bending these distorted crosssectional pipes to the required circular configuration because, whilethe expanding shoes tend to initially bend the portion of the distortedpipe of lesser diameter and eliminate distortion, the shoes will notautomatically center themselves in the pipe due to the gripping actionof the shoes against the pipe and therefore the ultimate shape of thepipe section will not be circular.

The present invention is directed to an internal welding clamp whichwill permit the shoes, when aligning distorted pipe sections ofconsiderable length, to be automatically centered within the sectionsand thereby shape the distorted pipe sections into a circularconiiguration. Apparatus for carrying out the invention as shown anddescribed in this application includes a moveable frame having wheels orthe like to enable the frame to be moved and positioned within the pipesections to be welded. The frame carries a handoperated drive shaftwhich is interconnected with a plurality of circularly spaced togglearms. The toggle arms are adapted to be expanded and contracted inaccordance with rotation of the shaft.

Each toggle arm carries an arcuate supporting shoe which is adapted otbear on either side of the joint between adjacent ends of the pipesections and align the same in proper welding position. To permittheshoes to be centered in distorted pipe sections the drive shaft isallowed to float within the frame. That is, one end of the shaft issuitably pivoted in a ball socket while the other end is supported in aresilient rubber cushion, rl`his States Patent 2804,83@ Patented Sept.3, 1957 construction permits the shaft to move or lloat during theexpanding operation and thereby center the shoes within the pipesections.

In a second embodiment of the invention the pivotal movement of theshaft is cushioned by inserting the forward end of the shaft within thesocket-shaped end of a stud. As the shaft pivots, it tends to pivot thestud against the force of a coil spring. The action of the spring tendsto cushion the pivotal movement of shaft and serves to realign the shaftin an axial relation with the frame when the shoes are collapsed out ofcontact with the pipe sections.

The present apparatus is also provided with preliminary positioningmeans which consists of a spring loaded roller associated with each shoeto initially contact the pipe sections and maintain the apparatus inposition therein before the shoes are expanded outwardly into clampingengagement with the pipe sections.

Other objects and advantages of the invention will appear in the courseof the following description.

In the drawings:

Figure 1 is a side elevation with parts broken away in section of thealigning clamp in the expanded position within the pipe sections;

Figure 2 is a transverse section taken along line 2 2 of Figure l;

Figure 3 is a rear elevation view of the clamp disposed within the pipesections and shown in the contracted position;

Figure 4 is an enlarged detailed section of the floating drive shaft;

Figure 5 is an enlarged detailed section of one of the positioningmembers taken along line 5-5 of Figure 1;

Figure 6 is an enlarged fragmentary section of the floating shaft 0f thesecond embodiment with the apparatus being in the collapsed position.

Figure 7 is a view similar to Figure 6 of the second embodiment showingthe pivotal action of the shaft occurring when aligning pipe sections ofdistorted cross sec* tional contour.

Referring ot the drawings there is shown in the first embodiment anapparatus for use in internally aligning the adjacent ends of two pipesections to be welded. The apparatus is adapted to be expanded intocontact with the underside of the joint between the adjacent ends of thepipe sections to position the same in proper welding alignment and toback up the molten weld metal during Welding.

The apparatus comprises a moveable tubular frame 1 which is providedwith suitable wheels 2 or the like to facilitate movement of the frameWithin the pipe sections 3.

The frame is maintained in firm contact with the internal surface of thepipe sections by a spring loaded roller 4 which is rotatably secured tothe upper arm of the frame and is biased outwardly into contact withpipe section 3.

The forward portion of frame 1 carries an enclosure which serves tohouse the expandable clamping mechanism. The enclosure includes agenerally conical rear closure ring 5, a forward closure plate 6 and aplurality of connecting circularly spaced guide blocks 7.

Rear closure ring 5 is provided with an annular base flange 8 to whichthe upper arm of frame 1 is connected by V-bracket 9 and to which thelower legs of frame 1 are connected by brackets 10.

Closure plate 6 is disposed forwardly of and parallel to flange 8.

Guide blocks 7 which connect plate 6 and flange 8 are provided withradially extending side edges and are' secured between plate 6 andflange 8 by bolts 11.

A plurality of circularly spaced supporting shoes 12 are adapted toslide radially between plate 6 and flange 8 and bear against the pipesections 3 on either side of the joint between adjacent ends thereof toalign the sections in proper welding position. The Shoes 12 aremaintained in alignment during the radial movement by providing theforward portion of each shoe with .a vpair of .side flanges 13 which areguided within guideways formed in the forward radial edge portion ofadjacent guide blocks 7.

The outer porti-onof each shoe liares circumferentially to provide agenerally arcuate head 14 having an outer curvature conforming to thecontour of the pipe sections to be welded.

.A segmental chill ring 15 is carried 4by the shoes .12 and is adaptedto be disposed beneath the underside of the joint between pipe sectionsto support the molten weld metal during welding. The arcuate segments.16 of ring 15 are each disposed within a peripheral groove formed inthe outer surface of .each head 14 and lretained therein yby keeper .bar17 and bolts 18.

The ends of each chill segment 16 are beveled as shown in Figure 3. Thebeveled ends of each alternate chill segment converge inwardly towardthe body portion of the correspond-ing shoe to which they are attached.In distinction the beveled ends of each intermediate adjacent segmentdiverge inwardly 'away from the body portion of the shoe to which theyare attached.

This yconstruction permits each alternate shoe 12 to be withdrawnradially relative to the intermediate adjacent shoes with the beveledends of one segment 16 sliding against the beveled ends of adjacentsegments during the radial movement.

To properly form the underside of the weld bead at the joint andeliminate any problem of the chill ring sticking to the weld metal, aflexible inert backing strip 19 may be disposed on the outer surface ofchill ring 16. Strip 19 `projects a slight distance outwardly beyond theheads 14 of shoes 12.

Each shoe 12 is pivotally connected to the outer extremity of v011e of aplurality of toggle arms 20. Toggle arms 20 are adapted to be expandedand contracted to move the shoes 12 radially toward and away from vthepipe sections 3.

When the toggle arms 20 are in the expanded position the vbeveled endsof each chill segment 16 are in lapping contacting yrelation with thebeveled ends of adjacent `segments -to provide a continuous chill ring15. As the toggle arms 20 are contracted, each alternate Vshoe 12 ispositively drawn inwardly `while the intermediate shoes are yieldablydrawn Ainwardly due to the yielding connection between the intermediateshoes and the corresponding .toggle arms similar to that .described'inthe Vcopending application of Althos M. Croswell, .Serial No. 298,391filed July 1l, 1952, now Patent No. .2,780,194 issued February 5, 1957,and entitled internal Back-up Clamp for Girth Welding. l

As the alternate segments 16 are drawn 'inwardly before the intermediatesegments, the beveled ends of the alternate segments slide `against thebeveled ends vof intermediate segments and `effect =a contraction of thechill ring 15 to a lesser diameter.

The inner ends of the toggle arms 26 are 'pivotally attached :to acentral hub 21 which is suitably secured to an insert nut 22. Nut 22 isthreadedlylengaged on `the central portion of a shaft '23 and rotationof the shaft causes .nut .22 to move forwardly or vrearwardly thereondepending on the vdirection of rotation of 'shaft 23 to expand 4orcontract .toggle arms 20.

Shaft 23 is mounted for pivotal movement within a rear vbearing housing24 secured within Athe apex .opening of rear closure ring 5. The rearportion of shaft 123 is journaled -within a bearing 125 having anoutwardly extending lflange l26 with a rear surface of generallyspherical contour. The spherical surface of vbearing ange 26 is adaptedlto :rotate .withinthe spherically contoured bottom surface of the axialrecess in housing 24 as a ball and socket joint. This constructionpermits the shaft 23, and shoes 12 which are interconnected to shaft 23,to pivot relatively to the frame 1 and attached housing 24.

Forward closure plate 6 is provided with an axial opening which receivesa forward bearing housing 27 within which the forward end of drive shaft23 is rotatably secured.

Housing 27 is generally cup-shaped in configuration havingacentralrecess 2.8 and an axial opening 29 in the base thereof whichcommunicates with said recess. The base portion of housing 27 is weldedwithin the opening in plate 6 and the open portion of recess 28 facesforwardly away from the frame 1. The open end of housing 27 is enclosedby -plate 30 which is secured to the housing by suitable bolts.

The forward end of shaft 23 extends through the opening 29 and isjournaled within a bearing 31 disposed within recess 28.

To permit the shaft 23 to float within forward'housing 27 as the shaftpivots at rear housing 24, axial opening 29 is provided with asubstantially greater diameter than shaft .23 and an annular resilientcushion 32 formed of rubber or the like is disposed in the space betweenshaft 23 and the wall of housing 27 and retained therein by ring 33.This construction permits .the shaft 23 and bearing 31 to move vor oatwithin housing 27 against the resiliency of cushion .32 as the shaft 23pivots within housing 24.

To prevent rearward movement of shaft 23 as the toggle arms .20 vareexpanded, the shaft is provided with an annular Aflange 34 which .isadapted .to bear against a thrust bearing 35. Bearing 35 is disposedwithin the axial .recess .of Vhousing .24.

The Abearing pressureof yflange 34 against thrust bearing 35 may be.regulated by means of an adjustment of spacing nut 36 and lock nut 37which are threadedly engaged on shaft 23. Adjustment of nuts 36 and 37controls vthe vlongitudinal play `or movement of the shaft.

`Shaft 23 is rotated by means of an operating rod 38 which isconnectedto the rear endof shaft 23 by clevis 39. Rod 38 extends beyond the endof the pipe section within Iwhich itis disposed .in position to bemanipulated by the operator.

The floating shaft permits the present apparatus to effectively 'alignpipe sections which are distorted in cross sectional shape. For example,when the apparatus is inserted :Within apipe section which is ov-al,elliptical or otherwise .irregular .in contour, the center of the,apparatus, .namely the shaft 23, is not aligned with the axis of thepipe .due to .the .irregular contour of the same. As the shaft 23 ismisaligned with the axis of the -pipe some of `the shoes .12 willcontact the pipe before yother shoes when the toggle arms 20 areexpanded. With the present floating shaft the unequal force of thevarious shoes against the pipe will cause the shaft 23 to move until theforce Yof .yall the shoes against the pipe is substantially equalized.When .this occurs .the portion of shaft 23 in the .same transverse:plane as shoes 12 will be aligned with the axis of the 'pipe sectionsrand the adjacent pipe ends may die bent to a circular shape Iandaccurately aligned rby the shoes.

The present apparatus is maintained `in proper welding v.alignmentwithin .one zof said pipe sections while the second pipe section is.brought into .an end-to-end relation with the first by a preliminarypositioning member carried by each shoe 12.

Each positioning member comprises a .generally .cylindrical housing :40which is :closed `at its inner end by a wall 41. .A plunger 42 Lisadapted to slidably move within housing 40 and the inner reduced end ofthe plunger extends through an opening in "wall 41 and is threade'dlyengaged `by a suitable nut to limit the outward movement of the plunger.'The outer end of each plunger treatisev 42 is bifurcated and a roller43 is rotatably secured between the prongs of the plunger by a pin 44.Rollers 43 are disposed transversely to this axis of the pipe sections 3and are adapted to be brought into contacting relation with saidsections to prevent longitudinal movement of the apparatus therewithinprior to the actual clamping engagement by shoes 12.

Rollers 43 are maintained in the proper transverse relation to the axisof the pipe sections by the slidable engagement of one end of pin 44within a slotted keyway 45 in the inner surface of housing 40. Pin 44 isfree to slide longitudinally within keyway 45 but rotational movement ofthe pin 44 and plunger 42 is prevented.

Plunger 42 is normally urged outwardly by a spring 46 which encirclesthe inner reduced portion of plunger 42 and bears between the bifurcatedhead of the plunger and wall 41. Thus roller 43 normally projectsoutwardly of housing 40 due to the force of spring 46.

Each housing 40 is connected to the rearward surface of the respectiveshoe 12 by a pad 47. When the -apparatus is in the contracted positionthe rollers 43 are biased outwardly beyond the outer surface of therespective shoes 12.

The apparatus, in the collapsed position, is inserted i within one ofthe pipe sections 3 to be welded and properly aligned behind the edge ofthe pipe. The toggle arms are partially expanded by operation of rod 38until the projecting rollers 43 are in contact with the pipe section. Atthis time the shoes 12 are not in contact with the pipe sections but theapparatus will be prevented from moving and maintained in alignment bythe pressure of rollers 43 against the pipe section.

The second pipe section is then brought into proper end-to-end relationwith the rst section so that backing strip 19 is aligned behind thejoint between the adjacent ends of the pipe sections. It is during thisperiod that the positioning members function most effectively. Once thesecond pipe has been brought into an end-to-end relation with the firstit is virtually impossible to properly align the clamping apparatusbeneath the joint between adjacent pipe ends because of the extremelength of the pipe sections. Therefore it is best to align the apparatusbeneath the edge of the first section and hold the appa4 ratus in thisaligned position by means of the positioning members until the secondpipe section is brought to the first and the shoes are expanded to clampboth sections in proper welding alignment.

The toggle arms 20 are then further expanded causing shoes 12. to movetoward the pipe sections and forcing plunger 42 inwardly against theforce of spring 46. It is at this time, as the shoes 12 move outwardlybut are still out of contact with the pipe sections that the positioningmembers serve a second function. If the pipe sections have an irregularcross sectional contour, the rollers 43, bearing against the pipesections under the force of springs 46, will ride on the inner surfaceof the pipe sections and tend to center the apparatus within thesections. However, once the shoes 12 come into contact with the pipesections the rollers will not ride on the surface of the pipe sectionsdue to the biting or gripping force of the shoes against the sectionsand the centering action of the rollers 43 is ended.

The positioning members lare able to satisfactorily center the apparatusWithin pipe sections having small irregularities in contour, but whenthe pipe sections have substantial deformations the action of oatingshaft 23 is necessary in order to have each shoe 12 bear against thepipe sections with equal force and thereby accurately align thesections.

A modification of the present invention is shown in Figs. 6 and 7.

In this embodiment the pivotal movement of shaft 48, corresponding toshaft 23 in the first embodiment, is cushioned by adapting the forwardend of shaft 48 to pivot a stud 49 against the force of a spring as theshaft itself pivots. The forward end of shaft 48 extends through axialopening 50 in cup-like housing 51, corresponding to housing 27, and isencircled by a knob-like bearing 52. Bearing 52 is disposed within thesocket-shaped end 53 of stud 49.

The forward end of housing S1 is closed off by a cover 54 which issecured to housing 51 by bolts 55, and the stud 49 extends forwardlyfrom housing 51 through an axial opening 56 formed in cover 54.

The outer shoulder of the socket-shaped end 53 of stud 49 is maintainedin bearing engagement with cover 54 by a spring 57 which encircles thecentral portion of stud 49 and is interposed between the Aouter surfaceof cover 54 and a spring retainer 58. Spring retainer 58 is disposed onthe `stud 49 and retained thereon by the threaded nut 59 which engagesthe threaded forward end of stud 49. Adjustment of nut 59 on the stud 49controls the compression of spring 57 and determines the force requiredby shaft 4S to pivot stud 49.

As seen in Fig. 6, the toggle arms 60 are in the inward collapse-dposition and shaft 48 is maintained in axial alignment with the housing51 by the force of spring 57. As the toggle arms 60 expand and the shoescontact the pipe sections the shaft 48 tends to pivot within housing 61in order to equalize the bearing force of the shoes against the pipesections.

As shaft 48 pivots the `outer end of the shaft moves radially relativeto housing 5l and pivots stud 49 against the force of spring 57. This isseen in Fig. 7. The action of spring 57 eectively cushions the pivotalmovement of shaft 48 and also serves to return the shaft to the axiallyaligned position thereof with respect to housing 51 when the toggle arms60 are contracted.

Various embodiments of the invention may be employed within the scopeyof the following claims.

l claim:

1. An internal aligning Vclamp for use in aligning the adjacent ends oftwo pipe sections disposed in end-to-end relation which comprises, amovable frame adapted to be disposed within said sections, 1a rotatabledrive shaftY pivotally carried by said frame, a plurality ofreciprocable members inter-'connected with said shaft and adapted to bemoved outwardly and inwardly with respect to the shaft in accordancewith rotation of the shaft, an arcuate shoe secured to the outer end ofeach reciprocable member and adapted to be moved radially -outwardlyinto contact with the sections on either side of the joint therebetweento align the same in proper welding position, roller means disposedtransversely to said drive shaft and resiliently mounted to said shoesand adapted to bear against one of said pipe sections, said roller meansserving to initially secure the frame against longitudinal movementwithin the pipe sections when the shoes are out of Contact with said`sections and tending to axially align the frame within said -sectionsas the shoes move into contact with said sections, said shaft pivotingwith respect to the frame when said shoes come into engagement with saidpipe sections to enable the shoes to bear against the pipe sections withsubstantially uniform pressure and align said sections in proper weldingposition.

2. An internal aligning clamp for use in aligning the adjacent ends oftwo tubular sections disposed in end-toend relation and beingsubstantially distorted in crosssectional shape which comprises, amovable frame adapted to be disposed within said sections, a rotatabledrive shaft pivotally carried by said frame, a plurality of reciprocablemembers inter-connected with said shaft and adapted to be movedroutwardly and inwardly with respect to the shaft in accordance withrotation of the shaft, an arcuate shoe secured to the outer end of eachrecipro-cable member and adapted to be moved outwardly `into contactwith the sections on either side of the joint therebetween t-o align thesame in proper welding position, resilient means secured to said shoesand adapted to bear against the interior wall of one of said pipesections for securing the esos-,sse

for tendingV to' axially align the frame within saidI sec-vv tions asthe shoes nieve" into contact with' said sections', a pair ofjournalling members mounted within saidl fratie with said drive shaftrotatably secured between said journalling mem-bers, means associatedwith' one' of said journalling members effecting pivoting of the shaftas said shoes come into engagementwith said' pipe sections to en= ablethe shoes to bear against said sections with' uniform pressure, andmeans associated with said other journalling member for cushioning the`pivotal movement of said shaft.

3". An internal' aligning' clamp for use'v in aligning' the adjacentends of two tubular sections disposed in end-toend relation which'-comprises, a-movable frame adapted to be disposed within said sections,`a` drive shaft carried by said frame, means to drive said shaft aV`plurality o`f reciprocable lmembers inter-connected with said shaft andadapted to be moved outwardly and inwardly' upon the driving of saidshaft, an arcuate shoe Sejcuredtotheouter end of each reciprocablememberandadaptedlto be moved radially outwardly upon; reciprocation ofl saidrmember into contact with' thef sections orreither side of the jointtherebetween to' align the same in proper welding posi'- tion, andpivotable bearing means supporting said' shaft withinl said frame toeifect pivoting of said shaft in relation to said framev as said shoescomeinto engagement with saidv sections to'l enable thel portion of thekshaft in the same transverseV plane `as Said shoes to bev centeredwithin the sections and permit each of said shoes to bear against saidsections' with substantially equalr force.

4. An internal aligning' clamp for use in aligning the adjacent ends oftwo tubular members disposed in end-toend relation which comprises', amovable frame adapted to be disposed within said sections, a drive shaftcarried by said frame, means to'rotate' saidy shaft a plurality ofreciprocable members inter-connected with said shaft Iand adapted to bemoved radially outwardly and inwardly with respect to' the shaftl uponrotation'V of theV shaft, an arcuate shoe secured to the outer end ofeach reciprocable member and adapted' tobe moved outwardly upon re=ciprocationof saidmember's intocontact with thes'ections on either sideofthe joint therebetween toalign the same in properwelding position,pivotable bearing means'supporting the' shaft' Within said frame andfulcruming one' endof said shaft asv the' shoes come into engagementwith said-sections-to permit said shaft to pivot in relation to'isa'idframe and enable the shoes to 'bear against thepipe sections withsubstantially uniformA pressure, and bearing means supported within saidframe and,- cushioning the other end of ysaid'shaft as-the same'pivots;Y

5. An internal aligning clamp for use' in aligning the' adjacent ends oftwo' tubular sections disposed in end'- to-end relation which comprises,a` movable frame adapt'- ed tobe disposedwithin said sections, a driveshaft carried bysaid' frame, means to drive said shaft a plurality ofreciproca'ble members interconnected with said shaft and adapted` to bemoved outwardly and inwardly' upon the driving of said shaft, an arcuateshoe secured tothe outer endV of each reciprocable member andadapted tobe moved radially outwardly upon reciprocation of4 said member intoContact with' the sections on eithery side of the joint-- therebetweentoalignlthe same in proper welding position, a pair: off journallingmembers connected to said frame', said drive shaft being rotatablysecuredE within said journalling members, means associated with one ofsaid journalingY membersl effectingV pivoting ofsaid shaft when saidshoes Contact' said sections to enable each ofA said shoes' to. bearagainstthe pipe sections with substantially' uniform pressure andl bendsaid sections to a' generally circular cross sectional shape, a housingtoy enclose the other of said'journallingr.membersl and spaced.outwardly therefrom with a clearancetherebetween, and;

8 a resilient ring' disposed within said clearance for cushinning the'pivotal movement of said shaft.

6. interna-i aligning clamp for use inaligning the adjacent ends'L oftwo tuliuiar' members disposedl in endto'Le'ntl relat-i'orl whichYcomprises, a'- pl'u'r'alit'y' of4 a-rcdateci-reum-fe'retially spacedsupporting members adaptedl tobe disposed within said tubular membersand tobemove'd radially outwardly irt'o contact with said tubularYmembers on;` either sid'e o'f' the jointv therebetweento` align thesame' in' proper welding posit-ion', an arm secured to each supportingmember andi entendi-ng" inwardly therefrom, means actuating each anni'to movethe supporting members radially, rollen means" secured to saidsupporting members andi adapted to*- be'ar against one of said tubularmembers for securing said clamp against longitudinal movement withinsai'd tubular members when said? supy` porting members aref out o'fcontact with said tubular c-iated with the roller means permitting'r'e'tfactiiii of the: roller means inwardly as sa-i'd supporting"members* move intoI contact with said tubular membersl A 7. Arilinternal'y aligning clampI for use in aligning the adjacent ends of twotubular sections disposed in endto-e'nd relation which cor-iiprises, amovable frame adapted to" be? disposed within' said? sections,- arotatable driveshaft carried? la'yf said frame,- a plurality ofreciproeable members irte'rf-tfonrieotedE with saidv shaft and adaptedto'b'e" m'o've'd outwardlyan'd inwardly in accordance with rota-tion ofthes'liaf@ anarci-nate sh'oel secured to' the outer e'n'd of each're'ciproeable member! and adapted tov be rho'v'e'd ntlwafdly" i'rl'toicontant with the' sections on either side of the joint therebetween'- toalign the samein proper weldirig position, a generally hollow' casingseoured to the? side suifaee of! each shoe; a` plunger mounted forisliding movement within'x each1 casing and springbiased' outwardlytherefrom-,- and a roller rotatably sec'ur'ecl to the outer? e'nd ofeach plunger, said rollers disposed transversely t'o said shaftandadapted to bear against said-` sections and securesaid frame against1ongitudina'l movement within said"l sections when' the' shoes are outof contanti with said sections and adapted to retract inwardly asltleshoes: move into/contact with said pipe sections 8. AnI interinalialigning clarripl for use in aligning the adjacent en`d's` of twotubular sections disposed in= end-toend relation which corr'ip'rise's,na movable frame adapted to be disposed within'said seet'ions, arotatabledrive shaft carriedI by said frlar'n'ej,Y means to? rotate said shaftaplurality oreciprocable members inter'connected with said shaft andadapted to' be moved? outwardlyy and in"- war'dly upon rotation of thes'haft, an arcuate supporting. shoe secured tot the outer endl o'fl cachreciprocahle member and?- adapted to bei moved outwardly uponreciprocation' ofL each member into Contact with the pipe sections'oneithera sideof the joint therebetween to align the same' ini propenwelding position, pivotable bearing means associated with the' framelfor fulcr'u'ming one end ofthe shaft as: said shoes. come intoengagement with said' sections to' permit said shaft to pivot and enablesaid shoes to bear against said sections with substantially equalforcega` pivota'ble member having a generally socket-shaped end: toreceive the other end of said shaft, and 'spring meansv associated' withsaid pivotable member for urging'. saidl member" into' axial; alignmentwithl said frame; saidv shaft' being! adapted to" pivot said pivotablemember against the' force ofsaidv spring means as the shaft' pivots withsaidspring' means serving to' cushion the'pivotal movement oi saidishaftau'd serving to axially align the shaft with said frame'wh'entheshoes are moved outf ofi eng-argomenti withlsaid sections.A

9. An internal aligning clamp for application across' two pipe sectionsdisposed' inendltt-end relation for prises, ai movable-v framel adapted.to beiV disposedf within the pipe sections and having a longitudinalaxis substantially coincidental with that of the pipe sections, a shaftpivotally carried on the longitudinal axis of the frame, a plurality ofarcuate shoe members spaced circumferentially about the shaft andadapted to be moved radially in a common plane into and out of contactwith the joint between the pipe sections, means interconnecting eachshoe member and the shaft for actuating the shoe members radially, andretractable positioning means provided on said shoe members and adaptedto bear against the pipe sections to initially secure the frame againstlongitudinal movement within the sections and retract as the shoemembers move into engagement with the sections, said shaft pivoting withrespect to the frame as the shoe members contact the pipe sections toenable the shoe vmembers to bear against the sections with substantiallyuniform pressure and align said sections in proper Welding position.

References Cited in the file of this patent UNITED STATES PATENTS2,353,868 Bisbee et al. July 18, 1944 2,413,103 Forbes Dec. 24, 19462,429,053 Forbes Oct. 14, 1947 2,452,867 Price et al. Nov. 2, 19482,587,940 Webster Mar. 4, 1952 2,594,000 Elliott Apr. 22, 1952 2,615,413Adams et al. Oct. 28, 1952 2,615,414 Adams et al. Oct. 28, 19522,638,069 Mearns May 12, 1953

